Polisher



April 9, 1963 A. A. HUTCHINS POLISHER Filed Feb. 15, 1960 INVENTOR. ALMQ A. Hu TCH/NS ATTO'R N EY Filed is, rose, so. No. arse 2 claims. or. 15-37) This invention relates to improved polishing apparatus, particularly adapted in certain respects for use in polishing and/ or cleaning the body of an automobile, or any other surface to which it may be desired to give a protective coat of polish.

in waxing or polishing an automobile by means of a conventional power driven polisher, it is customary to utilize a pad formed of lambs wool or cloth, which pad engages the surface of the automobile or other work surface being treated, and is continuously rotatably driven apply polish or cleaner to that surface. As the pad otates very rapidly, the operator gradually moves the nt're tool along the Work surface, to in this Way ultimately contact and polish or clean every portion of that surface.

Though devices of this general type have proven fairly satisfactory under some circumstances for polishing automobiles, these devices have nevertheless had certain very decided disadvantages in use, and have not been capable of effecting an optimum polishing action. This inadequacy has resulted primarily from the fact that the very rapidly turning pad has had a tendency to produce swirls or circular marks in the surface being treated, and it has been very difficult if not impossible to manipulate the tool in a manner preventing e formation of such swirls. Further, the s eed of rotation of the pad has been so great that the pad can very easily wear through or damage the painted surface of an automobile if the tool is left in engagement with a particular portion of that surface for too long a period, and consequently the operation of a power driven polisher of this character has required a very substantial amount of skill or practice on the part of the operator.

The general object of the present invention is to provide a new type of power driven polisher unit which is capable of very efiectively polishing or cleaning a work surfac and will do so without the above discussed disadvantages of prior polishing devices. A tool embodying the invention is specifically designed to produce a type of polishing action which is much more gentle than that of the conventional rapidly rotating pad, and which does not cause swirls or circular marks on the work surface being treated. Further, a device constructed in accordance win the invention is sufficiently gentle to eliminate the possibility of ever wearing through or damaging the paint on a work surface even if the tool is inadvertently left at a particular location on the work surface for a very extended period of time. Besides these advantages,

the pad which is employed in the present invention is of a unique character such that the construction of the pad itself, taken in conjunction with the manner of movement of the pad, acts to greatly facilitate the completely uniform distribution or spreading of the polishing compound or cleaning compound over the entire area of the Work surface.

in order to attain these results, I utilize as the work engaging pad of the polisher device a flexible body of cellular sponge material. This pad is so constructed that the sponge material itself directly engages and rubs the work surface being treated. Preferably, the sponge material is mounted to be bodily revolved about a predetermined by an associated rotary power tool, but is soconnected to the tool that the pad does not rapidly rotate about its own axis in use. In this way, a very gentle rubbing action is attained which can not damage or form assists swirls on the work surface. Also, this type of bodily revolving movement of the pad, without rotation of the pad about its own axis, allows the discussed type of sponge material to be employed without damage to the sponge material such as would occur if that material by itself were used as the pad in a simple rotating polisher arrangement. A particular advantage of the employment of a sponge material as the work engaging pad resides in the fact that the polish or cleaning compound may be received very conveniently within the pores of the spong material, and be automatically fed from those pores onto the work surface as the polishing action progresses. The inherent flexibility and resilience of the sponge material also is of great advantage, in allowing the pad to conform very completely to the contour of the work surface, to thereby assure effective polishing or cleaning of the entire area of that surface.

For optimum results, the pad is preferably formed of regenerated cellulose sponge material. The particular cellulose sponge material which is presently preferred is that sold by E. I. du Pont de Nemours, which product is made by transforming cellulose derived from wood or cotton to a resilient porous sponge form, with vegetable fibers distributed within the sponge to integrate and reinforce it. The pad may be connected to the driving mechanism by means of a connector part attached to one side of the pad, this part typically consisting of a screw secured to the pad and projecting laterally therefrom. Excessive deformation of the pad in use is prevented by providing a backing plate resisting such deformation of the pad, this plate desirably being formed of an essentially rigid resinous plastic material. A particular feature of the invention has to do with the provision also of an intermediate sheet of elastomeric material, between the backing plate and the sponge pad, for preventing damage to the sponge material by engagement with the periphery of the backing element upon deformation of the pad.

The above and other features and objects of the present invention will be better understood from the following detailed description of the typical embodiments illustrated in the accompanying drawing in which:

FIG. 1 is a side view, partially broken away, of a polishing unit constructed in accordance with the invention;

FIG. 2 is an enlarged showing of the 'two sections of the polishing head;

FIG. 3 is a section taken on line 3-3 of FIG. 2;

FIG. 4 is an enlarged fragmentary section through the pad of FIGS. 1 to 3;

FIG. 5 is a reduced section taken on line 5-5 of FIG. 2; and

FIG. 6 is a view similar to FIG. 2 but showing a variational form of backing plate.

Referring first to FIG. 1, l have shown at 10 a. rotary power operated polishing tool, having a driven head structure 11 constructed in accordance with the invention. In this figure, the tool is illustrated typically as working on the surface 12 of a work piece, which may be the painted surface of an automobile. The tool i has a handle 13, carrying a control lever 14 by which the operation of an electrically energized motor within the main portion .15 of the tool is controlled. Energy may be supplied to the motor within body 15' of the tool through a power cord 16 connected into handle 13. The motor acts when energized to rotate a cylinder spindle 17 about the main axis 18 of the tool, this spindle 17 having an externally threaded connector shank portion 19 projecting [therefrom and centered about axis 18. The end surface 20 of the enlarged diameter portion of spindle 17 may extend directly transversely of axis 18.

The driven apparatus 11 includes a carrier member 21 which is removably connectable to spindle 17, and a work engaging pad 22 which is removably and rotatably connectable to carrier member 21. The carrier member may be a bodyof rigid metal, typically die cast aluminum, having at its upper side (as viewed in FIGS. 1 and 2) a threaded bore 122 extending downwardly into the material of carrier part 21, and centered about previously mentioned axis 18. The threads within this bore are desirably of uniform diameter along their entire length, and threadedly engage the shank 19 of spindle 17 to rigidly attach member 21 to the spindle. The upper transverse planar surface 23 of body 21 engages axially against surface 20 of the spindle, to limit the tightening action of the part 21 relative to the spindle.

At its underside, part 21 contains a cylindrical bore 24 (see FIG. 2) within which there are mounted two spaced ball bearing assemblies 25 and 26, separated by a spacer ring 27. The outer races of bearing assemblies 25 and 26 are tight forced fits within bore 24, to be frictionally retained within that bore. As will be apparent from FIG. 2, the cylindrical bore 2 4 and the contained bearings are centered about an axis 28, which is parallel to previously mentioned axis 18, but is offset or spaced laterally therefrom.

Bearings 25 and 26 mount a part 29 for rotation about axis 28 relative to the carrier part 21. For this purpose, part 29 has an elongated externally cylindrical shaft portion 30 projecting axially into the two bearings 25 and 26, and dimensioned to be a tight friction fit Within the inner races of the hearings to thereby be automatically held in fixed relation thereto. At its lower or axially outer end, part 29 has an enlarged diameter annular flange 31, with an intermediate diameter cylindrical surface 32 typically being formed between portion 30 and flange 31. About (this cylindrical portion 32 there is mounted an annular disc of sheet metal 33, which is a friction fit on surface 32, and which is held against flange v 31 by a washer 34, also a tight friction fit on surface 32. Axial movement of portion 30 of part 29 into the bearings is limited by engagement of an annular shoulder 35 on part 29 with the inner race of one of the bearings. This shoulder is so positioned that the washer 34 and disc 33 are tightly clamped between that inner race of the lower bearing and flange 31. Also, element 33 may if desired be splined or keyed to flange 31, so that part 29 may be held against rotation by manual engagement of element 33. At its periphery, disc 33 desirably has a short axially curved edge 36, which may be externally knurled or otherwise irregularized as shown to facilitate manual gripping of element 33.

Part 29 and the attached elements 33 and 34 all turn in unison about axis 28 relative to part 21. For attaching the pad 22 to this part 29, the latter contains an internal threaded bore 37, into which the threaded shank 38 of a screw 39 connected to pad 22 is threadedly connectible. Screw 38 has a lower enlarged diameter circul-ar head 40, by which the screw is retained against separation from pad 22. As has been previously mentioned, the pad 22 itself is for-med of a flexible cellular sponge material containing a large number of pores or air cells 41. The sponge material is resilient and normally returns by its own resilience to the configuration shown in FIGS. 1, 2 and 6. This pad is circular, being centered about axis 28, and having a typically cylindrical outer edge surface 42. The work engaging surface 43 of the sponge is normally planar, and disposed directly transvcrsely of axis 28, as is the opposite surface 44 of the pad.

For optimum results, it is preferred that the sponge material of pad 22 be a regenerated cellulose sponge material, desirably having rather fine pores. The pores 41 preferably are distributed through the entire thickness of the pad, and in particular some of these pores are exposed at the work surface 43 of the pad, and extend 4 upwardly into the pad from that work surface as seen in FIG. 4.

Head of screw 38 has a flat surface 45 engaging against the central portion of surface 44 of the sponge. Abutting axially against surface 44 of the pad about head 40 of the screw, there is provided an annular sheet of elasttomeric material, such as a freely flexible rubber, this sheet being of an external diameter slightly smaller than the external diameter of peripheral surface 42 of the pad. The pad 22 is backed up against deformation except at its periphery by an annular rigid backing plate 47, whose outer edge 48 is of a diameter somewhat smaller than the external diameter of rubber sheet 46. The axial thickness of the two elements 46 and 47 may correspond substantially to the axial thickness of head 49 of screw 38, with another smaller diameter circular disc '49 being attached to the upper side of disc 47, and having an opening at its center 50 just large enough to pass shank 38 but small enough to efiectively retain head 40 against movement away from pad 22. Elements 47 and 49 are both rigid and are desirably formed of a rigid resinous plastic rnaterial, such as a thermosetting phenolic reinformed by a fabric or other reinforcing material embedded in the plastic. All of the elements 46, 47 and 49 are centered symmetrically about axis 28, to maintain proper balance of the pad assembly about that axis. Also, the surface 44 of sponge pad 22 is cemented tightly to sheet 46, over the entire area of sheet 46, and similarly elements 46 and 47 andelements 47 and 49 are cemented or tightly bonded together over the entire area of their engaged portions.

The carrier part 21 is constructed to automatically counterbalance the offset weight of pad 22 and the other parts which are centered about offset axis 28. For this purpose, member 21 has a flange 51, which may be cut away or hollow as shown at 52 at the side of axis 18 toward which axis 28 is ofiset. At its opposite side, flange 51 may be solid for a sutficient extent to exactly counterbalance the weight of pad 22 and its associated mounting parts.

In placing the apparatus in use, the first step is of course to threadedly connect carrier part 21 to shank 19, and to the position shown in FIG. 1. The operator may then Wet sponge pad 22 with water, to give it maximum flexibility, following which a cleaning compound or polishing compound is applied to the Work engaging surface 43 of the pad (or to work surface 12 itself if desired). The cleaning or polishing compound is contained within the pores or voids formed in sponge pad 22 at its work engaging surface (see FIG. 4), to be automatically fed from those pores onto the work surface 12 as the polishing or cleaning action advances. With the apparatus thus prepared for use, the operator places pad 22 in engagement with work surface 12, and starts the motor by actuation of lever 14. The motor turns spindle 17 and its shank 19, and through the shank turns carrier part 21 about axis 18. As the carrier part turns, element 29 and the attached pad 22 revolve bodily about axis 18, but at the same time the part 29 and pad 22 turn about axis 28 relative to carrier member 21, so that pad 22 does not rotate in the usual manner about the pad axis relative to the work surface. Since the pad thus revolves bodily but does not rapidly rotate about its own axis, the pad does not form swirls on the work surface, and can not wear through or damage that surface. 'Further, the surface 43 of the pad can flex sufficiently to conform to different contours of work surface, and particularly the peripheral edge portion of the pad 22 and the engaged edge portion of rubber disc 45 can flex to engage and polish irregular contours of the work surface. This deflection of the edge portions of elements 22 and 46 is illustrated in broken lines in FIG. 2 at 53. The purpose of sheet 46 is to form a cushion between the sponge material of pad 22 and the edge 48 of backing plate 47, when the pad is bent to the condition represented at FIG. 2, to thus prevent the edge 48 of rigid element 47 from cutting into and thereby damaging the sponge material of element 22.

When it is desired to remove pad 22 from the carrier part 21 for any reason, the operator manually holds element 33 against rotation, and then can unscrew the pad by merely turning it and the attached screw 38 relative to element 33 and the attached part 29. In order to allow for this action, the screw 38 is of course suitably retained against rotation relative to sponge pad 22, as by cernenting head 40 rigidly to pad 22 and element 49.

FIG. 6 represents a slightly variational form of pad assembly, including a sponge pad 22a which may be identical with pad 22 of FIG. 2, and a screw 38a which may be identical to that shown at 38- in FIG. 2. Instead of the elements 47 and 49 in FIG. 2, the FIG. 6 arrangement utilizes a molded hard rubber rigid backing plate 47a, having a thickened central portion and a thinner peripheral edge portion. Between this rigid element 47a and the pads, there may be provided a flexible rubber sheet 46a corresponding to that shown at 46 in FIG. 2. The elements 22a, 46a and 470 are all securely bonded or cemented together across their entire engaging surfaces, to form an overall assembly very similar to that shown in FIG. 2, and capable of use in the same manner.

I claim:

1. Polishing apparatus comprising a rotary carrier member, connector means for attaching said carrier member to a rotary power operated tool in a relation to be driven by the tool rotatably about a first axis, said conhector means comprising threads on said carrier member centered about said first axis and detachably connectable to a threaded drive element of said power tool, a pad formed of flexible regenerated cellulose sponge material, and means mounting said pad to said carrier member for rotation therewith about said first axis and dfor rotation relative to the carrier member about a second axis extending generally parallel to but offset from said first axis, said pad having a work engaging surface at which said regenerated cellulose sponge material is exposed for direct rubbing contact with a work piece, said regenerated cellulose sponge material having pores extending into the material of the pad at said surface for containing a polishing substance or the like in contact with the work piece during said rubbing action, the periphery of said pad being defined by an outer edge thereof, said pad being large enough that said outer edge is spaced laterally from said second axis a radial distance several times as great as the lateral spacing of said first axis from said second axis.

2. Polishing apparatus comprising a rotary carrier member, connector means for attaching said carrier member to a rotary power operated tool in a relation to be driven by the tool rotatably about a first axis, a pad formed of flexible regenerated cellulose sponge material, and means mounting said pad to said carrier member for rotation therewith about said first axis and for rotation relative to the carrier member about a second axis extending generally parallel to but offset from said first axis, said pad having a work engaging surface at which said regenerated cellulose sponge material is exposed for direct rubbing contact with a work piece, said regenerated cellulose sponge material having pores extending into the material of the pad at said surface for containing a polishing substance or the like in contact with the Work piece during said rubbing action, said last mentioned means including a part mounted to said carrier member for rotation relative thereto about said second axis and having a threaded bore centered about said second axis, and a screw on said pad removably connectible into said bore to attach the pad to said part for rotation therewith about said second axis, the periphery of said pad being defined by an outer edge thereof, said pad being large enough that said outer edge is spaced laterally from said second axis a radial distance several times as great as the lateral spacing of said first axis from said second axis.

References Cited in the file of this patent UNITED STATES PATENTS 1,877,951 Norris Sept. 20, 1932 2,034,455 Baird Mar. 17, 1936 2,263,883 Livermont Nov. 25, 1941 2,279,673 Graenser Apr. 14, 1942 2,281,722 Smith May 5, 1942 2,332,936 Schlegel Oct. 26, 1943 2,417,620 Soderberg Mar. 18, 1947 2,472,781 Vosbikian et al. June 7, 1949 2,702,395 Zaiger Feb. 22, 1955 3,007,189 Crane Nov. 7, 1961 FOREIGN PATENTS 260,822 Switzerland Aug. 1, 1949 315,273 Switzerland Sept. 29, 1956 469,626 Italy Mar. 10, 1952 494,149 Great Britain Oct. 18, 1938 

1. POLISHING APPARATUS COMPRISING A ROTARY CARRIER MEMBER, CONNECTOR MEANS FOR ATTACHING SAID CARRIER MEMBER TO A ROTARY POWER OPERATED TOOL IN A RELATION TO BE DRIVEN BY THE TOOL ROTATABLY ABOUT A FIRST AXIS, SAID CONNECTOR MEANS COMPRISING THREADS ON SAID CARRIER MEMBER CENTERED ABOUT SAID FIRST AXIS AND DETACHABLY CONNECTABLE TO A THREADED DRIVE ELEMENT OF SAID POWER TOOL, A PAD FORMED OF FLEXIBLE REGENERATED CELLULOSE SPONGE MATERIAL, AND MEANS MOUNTING SAID PAD TO SAID CARRIER MEMBER FOR ROTATION THEREWITH ABOUT SAID FIRST AXIS AND FOR ROTATION RELATIVE TO THE CARRIER MEMBER ABOUT A SECOND AXIS EXTENDING GENERALLY PARALLEL TO BUT OFFSET FROM SAID FIRST AXIS, SAID PAD HAVING A WORK ENGAGING SURFACE AT WHICH SAID REGENERATED CELLULOSE SPONGE MATERIAL IS EXPOSED FOR DIRECT RUBBING CONTACT WITH A WORK PIECE, SAID REGENERATED CELLULOSE SPONGE MATERIAL HAVING PORES EXTENDING INTO THE MATERIAL OF THE PAD AT SAID SURFACE FOR CONTAINING A POLISHING SUBSTANCE OR THE LIKE IN CONTACT WITH THE WORK PIECE DURING SAID RUBBING ACTION, THE PERIPHERY OF SAID PAD BEING DEFINED BY AN OUTER EDGE THEREOF, SAID PAD BEING LARGE ENOUGH THAT SAID OUTER EDGE IS SPACED LATERALLY FROM SAID SECOND AXIS A RADIAL DISTANCE SEVERAL TIMES AS GREAT AS THE LATERAL SPACING OF SAID FIRST AXIS FROM SAID SECOND AXIS. 